Telephone receiver



June 21, 1927.,

DE EgBERT A. REYNOLDS TRELEPHONE RECEIVER Filed Feb.l9, 1925 2Sheets-Sheet 2 l INVENTOR, AMA W ATTORNEY,

Patented June 21, 1927.

" "UNITED- STATES PATENT OFFICE.

DE ELBER'r A. nEYnonDs, or'YoNKERs, NEW YORK.

TELEPHONE RECEIVE Application filed' February 19, 1925.; Serial no;10,166.

My invention relates radio receivers.

One of the objects ofmy invention is to, clarify the sounds emitted fromthe receiver which in prior construction gives use to dis-' sonant andother imposed sounds and to restrictthe vibrations of the receiversolely to pure tones in consonance with the sounds originally imposed onthe transmitter at the transmitting station. A vibrating 'diaphragm'held in proximity to the'tympanum of the ear for any considerable timebecomes most annoying and nerve-racking, which is not the case Wheresound is conveyed to the tympanum by a set of musical reeds, as I havediscovered from my invention;

A third object of this invention is to provide a sound-amplifyingrdevice specially adapted to radio reception with a more or lessextended scale, each reed responding to the respective frequencies and"thus reproducing with precision the original communication.

It is a recognized fact in telephone pracv30i tice that the usualreceiver deliversbut a small fraction of the sound engendered at thetransmitter. This shows the very low efficiency attained by thetelephone receiver ofthe ordinary construction. Upon analysis I havefound that this low efficiency is large ly due to the stiffness of theordinary ferro-,

type diaphragm employed in the receiver and that the energy of theelectric current is largely consumed by the intermolecular friction orinternal heat.v The usual diaphragm is held at its periphery, and uponapplication of energy at. its center, the re-' sulting vibrations areproduced at a great sacrifice ofthe electrical energy, and at best at: avery imperfect reproduction of the sounds transmitted; c I

A further limitation in the usual 'dia-' phragm receiver is found in therelatively restricted range of resiliency of the metals employed in itsconstruction; The limitations are imposed by the circularforin of thediaphragm and tendv to retard its vibrations,

practically excluding the harmonics, and thereby destroying the timbre,modulation and quality that distinguishes one voice from I to telephoneand responding amplitudes 0? this invention is to elimtransmittedsounds.

.invention there is no retarding influence,

since each reed responds to its cycle of vibrations and the reedscollectively. transform each electrical wave into the-respectivecomponent sound Waves with the corof the respective Perfect reproductionin a receiver at the lowest consumption of electrical energy is had bymy invention under'the conditions of the greatest freedom of thevibrating elements and with correct .attuniHg tothe frequenciesof theelectrical vibrations in har- Inony with the recognized scale of music.I In the preferred form of my invention, I

have provided a vbank or series of eight orv more vibrating metallicreeds, each attuned toa note in the musical scale, thus covering one ormore octaves and encompassing the range of the humanvoice in ordinaryconversation. These reeds are preferably secured to aplate ofnon-magnetic material having grooved openings corresponding to therespective sizes and lengths of the reeds, with a heel-plate or barresting firmly on one pole of the receiver to carry the magnetic flex tothe series. of reeds at or near the free ends of the reeds to attainfull attraction by the opposing pole of the receiver and cause the freevibration of the reeds compositel-y forming the transmittedcommunication.

hen employed as a sound amplifying receiver, the number of reeds may bemcreased to as many octaves as deslred. V The reedspmay'be stamped froma single piece of metal and attached to a bar forming a part of themagnetic circuit. It may also be found desirable to place the core ofthe voice-coil near the center of the setof reeds to cause the reeds tovibrate through a greater arc; a v c I Itwill also be noted that it isthoroughly practicalxto build the plate or disc with the reeds attached,as an article of manufacture, invaried forms to fit any make or style ofreceiver by merely substituting my invention for the ordinary receiverdiaphragm. I c .Further features and objects of my 1nvention will -bemore fully understood from companying drawings, in which t .Fig. 1 1s aside elevation'ofa telephone recelver. having its permanent magnet pro-'the following detail description and the acvided with poles set at anangle toward each other and a series of sound emitting reeds;

Fig. 2 is a sectional elevation on the line 22 of Fig. 1;

Fig. 3 is a sectional elevation on line 3 3 of Fig. 1;

Fig. 4 is an elevation of the series of reeds and mounting meanstherefor, as viewed from the reverse side shown in Fig. 3;

Fig. 5 is a vertical central section of a modification of my inventionadapted to a watch-case receiver or a unit of a radio headset or loudspeaker;

Fig. 6 is a sectional view on line 66 of Fig. 5;

Fig. 7 is a vertical central section of a further modification of myinvention adapted to a sound-amplifying reproducer; and

Fig. 8 is a vertical central section as viewed at right angles to Fig. 7

Referring to Figs. 1 to 4 of the drawings, my device comprises the usualreceiver shell or casing 10, having the usual removable, perforated head11. The pole pieces 12, 13 of the permanent magnet 14 are preferablylaminated as indicated in Figs. 1 and 2 and secured to the free ends ofthe respective poles 15, 16 of the permanent magnet 14 by the bolt 17and spacer 18. The voice-coils 19, 20 are suitably mounted on therespective pole pieces 12, 13. The pins or projections 21, 22 of theshell 10 of the receiver serve to hold the disc or other mounting of thevibratory elements as described more fully iereinafter.

In Fig. 3, 23 represents a disc of preferably non-magnetic materialhaving openings at 24, 25 torespectively fit the pins or pro jeetio-ns21, 22, and further provided with a series of openings 26correspondingin numher to the number of reeds, as will appear. The series of reeds 27comprise such number of the respective tones of the musical scale andadditional reeds as may be desired. Such reeds 27 are of resilientmagnetic material and each reed 27 is preferably rigidly attached to thedisc 23 by means of an iron rivet 28, extending through the disc 23, andconnecting with a bar 29 of magnetic metal as shown in Fig. 3. Such bar29 is of magnetic metal and of sufficient thickness to maintainpermanent engagement with one of the pole pieces, such as the pole piece12 as shown in Fig. 1. If desired, the bar 29 and the reeds 27 may beformed of one piece, as by stamping, and mounted on the disc 23 in therelation described hereinabove.

Such method of assembly provides a path for the flux of the permanentmagnet through the rivets 28 or the bar 29 to the respective reeds 27and the free ends of the reeds 27 areheld in suitable'proximity to theother pole piece 13. By reason of the non-magnetic character of the disc23, thereby having no magnetic influence upon the flux modified by thevoice coils 19, 20, the resilient reeds 27 respond freely through theopenings 26 in the disc 23.

Preferably, the reeds 27 are separately at tachedto the disc 23 and areof such lengths head-set, see Figs. 5 and 6, I prefer to at-,

tach the laminated pole pieces 30, 31 of the voice coils 32, 33 to apiece 34 of non-electrically conducting and non-magnetic mate rial ofV-shape, fitting between the free ends 36, 37 of, the circular magnet38, and arrange the ends of the pole pieces 30, 31. to directly engagethe respective poles 39, 40 of the circular permanent magnet 38. Theusual watch-case shell is indicated at 42. I prefer to provide the soundemitting perforation 43 ofthe head 44 of the shell 42 with a strip 45 offelt, suitably held to extend over the perforation 43 in slight tautrelation for the purposes and as is set forth in my copendingapplication entitled Modulating diaphragm, SerialNo. 712,918, filed byme on the 13th day of May, 1924.

The magnet 38 may be, remo-vablysecured within the shell 42 by the setscrews 46, 47.

The series or reeds 48 and a mounting disk 49 of non-magnetic materialcorrespond to the hereinabove described construction and arrangement. l

In a sound amplifying receiver, a plurality of permanent magnets 50 maybe employed and attached to a common laminated pole piece 51. Theextension of ma netic iron 52 is spaced by the recessed, non-magneticmaterial 52, and the same and the pole piece 51 are removably secured tothe free ends of the crmanent magnets 50 by the bolts 53. Any suitableform of casing 54 may be employed, preferably designed to deliver thesound from a druin-shaped cavity, a series of resounding partitions orthe usual, bridge-supporting sounding boards common violin construction.7

The series of reeds 55 are similar as hereinabove described and may bemounted on the disk 56' of preferably non-magnetic material. However, asindicated in Fig. 7, each reed 55 may be separately secured to themagnetic extension 52 by individual screws 57.

In the above various forms of my invention, it will be noted that Iprefer to arrange the pole pieces or the equivalent mag-- ncticallyacting upon the series of reeds, at an angle to one another, to therebylocate the pole piece which is magnetically spaced from the reeds, moreclosely toward the'frce ends of the reeds, and preferably uniformilyfrom their free ends. Preferably, as is particularly indicated in Figs.2, 3 and I when compared with one another, I arrange the bar connectingthe fixed ends of the reeds, to extend in substantial parallel relationto the other pole piece.

From the foregoing, the advantages of my construction and method ofoperation will be readily understood by those skilled in the art towhich the invention appertains.

WVhereas, I have described my invention by reference to specific formsthereof, it will be understood that many changes and modifications maybe made without departing from the spirit of the invention.

I claim 1. In a telephone receiver, an electromagnet, a set of reedshaving a common netic base mounted in contact relation with one pole ofan electro-magnet, the free ends of said reeds being disposed inmagnetic reiation to the other pole of said electro-magnet and means forelectrically attracting the free ends of said reeds.

2. In a sound-amplifying device, a permanent magnet, a% plurality ofvibrating reeds in magnetic contact with one pole of said permanentmagnet, a disc of non-magnetic material having a plurality of elongatedopenings for respectively receiving said reeds, an electro-magnetattached to the opposing pole of said permanent magnet, and coil meansfor operating said reeds by said electro-magnet.

3. In a sound-amplifying device, a plurality of permanent magnetshavinga common core, means of magnetic material se cured to said common coreof said permanent magnets in proximity with said electromagnet, a seriesof vibrating reeds attached to said means of magnetic material and meansfor electrically operating said reeds by the core of saidelectro-magnet.

4. In a sound amplifying device, the c0mbination of permanent magnetmeans, a set of pole pieces, coil means in electromagnetic relation withsaid set of pole pieces, a set of attuned reeds disposed in magneticrelation to said set of pole pieces and means of nonmagnetic materialfor fixedly supporting one end of said reeds respectively. I

5. In a sound amplifying device, the combination of permanent magnetmeans, a set of pole pieces, coil means in electromagnetic relation withsaid set of pole pieces, a set of attuned reeds disposed in magneticrelation to said set of pole pieces and means of non-magnetic materialfor fixedly supporting one end of said reed respectively, saidnonmagnetic supporting means being provided With recesses forrespectively receiving said reeds and permitting said reeds to vibratetherein.

' elation with said pair 6. In a sound amplifying device, the combination of permanent magnet means, a set of pole pieces, coil means inelectromagnet relation with said pair of pole pieces, a: set ofprogressively attuned reeds disposed in magnetic relation to said pairof pole pieces and means of non-magnetic material for fixedly supportingone end of said reeds relative to one of said pole pieces, the other ofsaid pair of pole pieces extending at an angle to said one pole piece.

7 In a sound amplifying device, the combination of permanent magnetmeans, a set of pole pieces, coil means in electromagnet relation withsaid pair of pole pieces, a set of progressively attuned reeds diposedin magnetic relation to said pair of pole pieces anc means ofnon-magnetic. material for fixedly supporting one end of said reedsrelative to one of said pole pieces, the other of said pair of polepieces extending at an angle to said one pole piece and substantiallyparallel to the free ends of said set of reeds.

8. In a sound amplifying device, the combination of permanent magnetmeans, a set of pole pieces, coil means in electromagnet of pole pieces,a set of progressively attuned reeds disposed in magnetic relation tosaid pair of pole pieces and means of non-magnetic material for fixedlysupporting one end of said reeds relative to one of said pole pieces,the other of said pair of pole pieces extending at an angle to said onepole piece and substantially parallel to the free ends of said set ofreeds, said non-magnetic supporting means having openings of progressivelength respectively receiving the reeds of progressive length of saidset of reeds.

9. In a sound amplifying device, the combination of permanent magnetmeans, a set of laminated pole pieces, coil means in electromagneticrelation with said set of pole pieces, a set of attuned reeds disposedin magnetic relation to said set of pole pieces and means ofnon-magnetic material forfixedly supporting one end of said reedsrespectively.

10. In a sound amplifying device, the combination of permanent magnetmeans, a set of laminated pole pieces, coil means in electromagnetrelation with said pair of pole pieces, a set of progressively attunedreeds disposed in magnetic relation to said pair of pole pieces andmeans of non-magnetic material for fixedly supporting one end of saidreeds relative to one of said pole pieces, the other of said pair ofpole pieces extend ing at an angle to said one pole piece andsubstantially parallel to the free ends of said set of reeds.

In testimony whereof I have signed this specification this 11th day ofFebruary 1925.

DE ELBERT A. REYNOLDS.

